The microstructural morphology of transformed α induced by <111> β fiber texture in a dissimilar inertia friction weld between near-α and α plus β titanium alloys

The microstructure and texture features of the dissimilar inertia friction welded (IFW) joint of Ti65 titanium alloy to TC25G titanium alloy were characterized. The beta textures in dynamic recrystallization zone (DRZ) produced by severe hot shear deformation were dominated by the bcc D-2(11-2)[111] shear texture for both the Ti65 and the TC25G alloys. The variant selection occurred during the beta alpha phase transformation at the final cooling stage, in which higher fraction of alpha variants with misorientation of [-10 5 5 3]/63.26(degrees) formed. The triangular configuration structures were frequently observed in the interior of the beta grains in DRZ, which was resulted from the variant selection occurring in microregion. The formation of triangular configurations was also favored naturally by the <111>(bcc) beta fiber texture.